Noun
the use of radio to send telegraphic messages (usually by Morse code)
telegraphy that uses transmission by radio rather than by wire
Source: WordNetHistory In 1901, Reginald Fessenden demonstrated a direct-conversion heterodyne receiver or beat receiver as a method of making continuous wave radiotelegraphy signals audible. Source: Internet
Enormous antenna loading coil used in a powerful longwave radiotelegraphy transmitter in New Jersey in 1912. Source: Internet
Today, due to more modern text transmission methods, Morse code radiotelegraphy for commercial use has become obsolete. Source: Internet
By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy by ships for both commercial purposes and passenger messages. Source: Internet